Sequential controlled start-up for zoned conveyor systems

ABSTRACT

The disclosure describes zoned conveyor systems with non-time based sequential power-up of different zones using defined current draw and speed threshold values and/or a defined number of motor revolutions of one conveyor zone to determine when to initiate operation of another (typically adjacent) zone.

RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalApplication Ser. No. 61/420,657, filed Dec. 7, 2010, the contents ofwhich are hereby incorporated by reference as if recited in full herein.

FIELD OF THE INVENTION

This invention relates to conveyor systems.

BACKGROUND OF THE INVENTION

Zoned conveyor systems are well known. See, e.g., U.S. Pat. Nos.5,285,887 and 5,228,558. U.S. Pat. No. 6,253,906 proposes the use of atime-based sequential release control system for zoned conveyors. Thecontent of each of the above patents is hereby incorporated by referenceas if recited in full herein. However, there remains a need foralternative ways to control zoned conveyor systems that can reduce powerspikes and/or dynamic loading associated with start-up.

SUMMARY OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention are directed to zoned conveyorsystems for transporting a series of loads. The systems include a seriesof conveyor zones including a downstream conveyor zone and a pluralityof upstream conveyor zones. Each conveyor zone includes at least onedrive motor for operating each respective conveyor zone to advance theloads along the conveyor system. The system also include a controlcircuit in communication with each at least one drive motor. The controlcircuit is configured to monitor during start-up for a respectiveconveyor zone at least one of: (i) current draw and speed of arespective drive motor as the motor goes from an unpowered state to anoperational state; and/or (ii) a number of revolutions of a respectivedrive motor as the motor goes from an unpowered state to an operationalstate. The control circuit is configured, after operation of theupstream and the downstream conveyor zones is stopped to maintainstationary any loads carried by the upstream and downstream conveyorzones, to resume operation of the upstream and downstream conveyor zonesby first initiating operation of the downstream conveyor zone, andsubsequently sequentially controlling initiation of operation of eachupstream conveyor zone. The control circuit is configured to initiateoperation of one of the upstream conveyor zones based on one of thefollowing: (i) when the drive motor of the conveyor zone downstreamtherefrom reaches a defined current draw and speed; or (ii) when thedrive motor of the conveyor zone downstream therefrom has reached adefined number of rotations, so that operation of each conveyor zone isinitiated in a controlled sequential manner in response to when thedrive motor of the conveyor zone downstream therefrom reaches thedefined current draw and speed or the motor has reached the definednumber of revolutions.

The control circuit can be configured to increase power to a respectivedrive motor at a constant rate of change from the unpowered state to theoperational state. The control circuit can be configured to direct thesequential operation using the monitored current draw and speed of arespective drive motor.

The drive motors can each include at least one integral Hall-effectsensor. The control circuit can be configured to direct the sequentialoperation based on motor revolution count using a pulse count detectedby the respective Hall-effect sensors.

The control circuit can be configured to ramp up at least one of thezones at a different speed from other zones to thereby operate withimproved power management and a smooth system ramp-up.

The control circuit can include a primary controller card thatcommunicates with drive motor controller cards at upstream anddownstream conveyor zones. The primary controller card can include anonboard processor that includes the sequential start-up logic andcurrent draw and speed threshold values used to determine when toinitiate start-up to the different zones.

The control circuit can be configured to operate with conveyor zoneshaving different ratio gear boxes with each respective gear box ratioassociated with a different number of rotations or current draw to raisethe drive motor and associated zone up to a desired speed.

Other embodiments are directed to controller circuit devices for a zonedconveyor system. The devices include a control circuit comprising asequential release operational mode for a zoned conveyor system having adownstream zone and a plurality of upstream conveyor zones incommunication with a drive motor for each conveyor zone. The controlcircuit is configured to monitor current draw and speed of therespective drive motors during start-up. In the sequential releaseoperational mode, the control circuit is configured to initiateoperation of the upstream conveyor zones based on when a drive motor ofthe conveyor zone downstream therefrom reaches a defined current drawand speed so that operation of each conveyor zone is initiated in acontrolled sequential manner in response to when the drive motor of theconveyor zone downstream thereof reaches a defined current draw andspeed.

The device can be a single controller card that is configured to controlstart-up of different conveyor zones using different defined currentdraw thresholds and speeds.

The device can be configured to cooperate with conveyor zones that havedifferent drive motors.

The device can include a motor temperature monitoring circuit that usesa predictive thermal model that considers whether a motor is associatedwith a zone is using dynamic braking to predict a temperature of themotor.

The device can include a motor control circuit with a plurality of lowside and high side FETs in communication with at least one drive motorof at least one conveyor zone. During no-load stops the low side FETscan be automatically turned on to reduce overshoot during the no-loadstops.

The device may include a look-up table of drive motors, gear ratios andassociated threshold values for speed and current draw used for thesequential release mode.

The control circuit can be configured to direct a respective drive motorto ramp up to speed at a constant ramp up rate.

The control circuit can be configured to direct different conveyor zonesto ramp up at different speeds while monitoring current draw.

The control circuit can be configured to direct a first upstreamconveyor to initiate operation based on first current draw level, anddirect a second upstream conveyor to initiate operation based on adifferent second current draw level.

Still other embodiments are directed to methods of operating zonedconveyor systems. The methods include: (a) stopping operation of adownstream and a plurality of upstream conveyor zones to maintainstationary any loads supported by the conveyor zones; and (b)automatically re-starting the conveyor zones by sequentially initiatingoperation of the downstream conveyor zone and the upstream conveyorzones by first initiating operation of the downstream conveyor zone, andsubsequently sequentially controlling initiation of operation of eachupstream conveyor zone. The re-starting step is carried out by: (i)monitoring current draw and speed of a drive motor associated with thedownstream conveyor zone; then (ii) automatically initiating operationof an adjacent first upstream conveyor zone when the downstream drivemotor reaches a predefined current level and speed; (iii) monitoringcurrent draw and speed of a drive motor associated with the firstupstream conveyor zone; then (iv) automatically initiating operation ofa second upstream conveyor zone adjacent to the first upstream conveyorzone when the drive motor of the first conveyor zone reaches apredefined current draw and speed. Operation of each conveyor zone isinitiated in a controlled sequential manner in response to when thedrive motor of a conveyor zone downstream thereof reaches a predefinedcurrent draw and speed during start-up.

The predefined current draw and speed for at least one conveyor zone canbe different from the others.

Still other embodiments are directed to other methods of operating zonedconveyor systems. These methods include: (a) stopping operation of adownstream and a plurality of upstream conveyor zones to maintainstationary any loads supported by the conveyor zones; and (b)automatically re-starting the conveyor zones by sequentially initiatingoperation of the downstream conveyor zone and the upstream conveyorzones by first initiating operation of the downstream conveyor zone, andsubsequently sequentially controlling initiation of operation of eachupstream conveyor zone. The re-starting step is carried out by: (i)counting a number of motor revolutions of a drive motor associated withthe downstream conveyor zone; then (ii) automatically initiatingoperation of an adjacent first upstream conveyor zone when thedownstream drive motor revolution count reaches a predefined level;(iii) counting a number of motor revolutions of a drive motor associatedwith the first upstream conveyor zone; then (iv) automaticallyinitiating operation of a second upstream conveyor zone adjacent to thefirst upstream conveyor zone when the drive motor revolution count ofthe first conveyor zone reaches a predefined level. Operation of eachconveyor zone is initiated in a controlled sequential manner in responseto when the drive motor of a conveyor zone downstream thereof reaches apredefined revolution count during start-up.

It is noted that the counting of revolutions can be directly determinedby counting the number of revolutions of the motor or a motor shaft orother component thereof. The counting can be carried out by counting thenumber of pulses associated with an optical or Hall-effect or othersensor.

It is noted that aspects of the invention described with respect to oneembodiment, may be incorporated in a different embodiment although notspecifically described relative thereto. That is, all embodiments and/orfeatures of any embodiment can be combined in any way and/orcombination. Applicant reserves the right to change any originally filedclaim or file any new claim accordingly, including the right to be ableto amend any originally filed claim to depend from and/or incorporateany feature of any other claim although not originally claimed in thatmanner.

These and other objects and/or aspects of the present invention areexplained in detail in the specification set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a controller device according toembodiments of the present invention.

FIG. 2 is a schematic illustration of an exemplary zoned conveyor systemthat can operate using the controller device shown in FIG. 1 accordingto embodiments of the present invention.

FIG. 3 is a top view of an exemplary zoned conveyor system that can usethe controller device of FIG. 1 according to embodiments of the presentinvention.

FIG. 4 is a schematic illustration of a zoned conveyor system that canuse the controller device of FIG. 1 according to yet other embodimentsof the present invention.

FIG. 5 is a schematic illustration of a data processing system accordingto embodiments of the present invention.

FIG. 6 is a block diagram of exemplary inputs and outputs for thecontroller device shown in FIG. 1 and/or the zoned conveyor systemsaccording to embodiments of the present invention.

FIG. 7 is a flow chart of exemplary operations that can be used tomonitor and control conveyor zones according to embodiments of thepresent invention.

FIGS. 8A and 8B are flow charts of exemplary Real Time Interrupts forzoned conveyor systems that can use a controller device such as thatshown in FIG. 1 according to embodiments of the present invention.

FIG. 9 is a diagram of a sensor interface circuit according toembodiments of the present invention.

FIG. 10 is a diagram of a power supply circuit according to embodimentsof the present invention.

FIG. 11 is a diagram of an upstream peer-to-peer controller according toembodiments of the present invention.

FIG. 12 is a diagram of a downstream peer-to-peer controller accordingto embodiments of the present invention.

FIG. 13 is a diagram of a system control circuit according toembodiments of the present invention.

FIG. 14 is a diagram of a motor control circuit according to embodimentsof the present invention.

FIG. 15A is a diagram of a main CPU circuit according to embodiments ofthe present invention.

FIG. 15B is an enlarged portion of the main CPU circuit shown in FIG.15A.

FIGS. 16-20 are flow charts of exemplary operations for each of fivestates for a transport zone with standard singulation according toembodiments of the present invention.

FIGS. 21-29 are flow charts of exemplary operations for each of ninestates for a transport zone with enhanced singulation according toembodiments of the present invention.

FIG. 30 is a schematic illustration of a data processing systemillustrating a Learn Displacement Mode according to embodiments of thepresent invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention will now be described more fully hereinafter withreference to the accompanying figures, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Like numbers refer to like elementsthroughout. In the figures, certain layers, components or features maybe exaggerated for clarity, and broken lines illustrate optionalfeatures or operations unless specified otherwise. In addition, thesequence of operations (or steps) is not limited to the order presentedin the figures and/or claims unless specifically indicated otherwise. Inthe drawings, the thickness of lines, layers, features, componentsand/or regions may be exaggerated for clarity and broken linesillustrate optional features or operations, unless specified otherwise.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms, “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes,” and/or “including” when used in thisspecification, specify the presence of stated features, regions, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, regions, steps,operations, elements, components, and/or groups thereof.

It will be understood that when a feature, such as a layer, region orsubstrate, is referred to as being “on” another feature or element, itcan be directly on the other feature or element or intervening featuresand/or elements may also be present. In contrast, when an element isreferred to as being “directly on” another feature or element, there areno intervening elements present. It will also be understood that, when afeature or element is referred to as being “connected”, “attached” or“coupled” to another feature or element, it can be directly connected,attached or coupled to the other element or intervening elements may bepresent. In contrast, when a feature or element is referred to as being“directly connected”, “directly attached” or “directly coupled” toanother element, there are no intervening elements present. Althoughdescribed or shown with respect to one embodiment, the features sodescribed or shown can apply to other embodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the present applicationand relevant art and should not be interpreted in an idealized or overlyformal sense unless expressly so defined herein.

The word “card” refers to a printed circuit board (PCB). The word“board” refers to a PCB of any shape, typically held in an enclosure forenvironmental and safety protections.

FIG. 1 is a schematic illustration of an exemplary controller device 10used for controlling zoned conveyor sections 100-103 (FIG. 2). Thedevice 10 is typically implemented as a single controller card, but mayalso be implemented as a plurality of cards thatelectrically'communicate. If the latter, the cards may be held by acommon mounting platform or may be distributed in different devices andlocations via wired or wireless connections. In some embodiments, theconnections may include LAN, WAN or Internet connections.

As shown in FIG. 1, the controller device 10 includes a primary(typically single) card 10 with on-board electronics 10 e and controllogic 10 c that can provide for Sequential Release Control for start-upand, optionally, a Singulated Release Mode. The controller device 10 canbe configured to mount to a conveyor zone (typically covered forenvironmental protection and user safety) using tabs 11. The controllerdevice 10 can monitor and control at least one drive motor 20 for arespective conveyor zone (100-103, FIG. 2). The conveyor zones typicallyinclude at least one drive motor 20 that drives a belt that moves theconveyor support surface, e.g., rollers. The drive motors 20 can bebrushless motors such as those used in motors associated withRollerDrive® motors for conveyor systems such as conveyor systems withintegrated electric motor and rollers and/or belts, available fromInterroll, Inc., Wilmington, N.C.

As shown, the controller device 10 can include a series of dipswitches10 s. The device 10 is configured to communicate with downstream andupstream peer-to-peer control circuits of associated conveyor zones,typically via controller cards 110 d, 100 u. The controller device 10can include one or more ports 20 p, 30 p and communicates with sensors30 associated with one or more different conveyor zones 100-105 (FIG.2). The sensors 30 can include position sensors 30, and a respective atleast one motor sensor 35 such as a current draw sensor for a drivemotor and/or a motor speed sensor. It is noted that the communicationswith or between local and/or remote components can be either wired orwireless.

The user interface dipswitches 10 d can be configured as shown in thetable below.

TABLE 1 Exemplary DipSwitch Configuration Switch Type On Off SW1 LogicPNP NPN SW2 Rotation CW CCW SW3 Singulation Enhanced Standard SW4Upstream Override Standard SW5 Downstream Override Standard SW6 MotorSelect Future, EC 120 EC 100, EC 110 SW7 Motor Select Future, EC 110 EC100, EC 120

The controller device 10 can be backward compatible to work with one ora plurality of different drive motors 20, including those with differentgear ratios such as the EC100, EC110 and EC 120 used in older conveyorsystems of Interroll, Inc. Examples of drive systems with drive motorsand idlers are described in U.S. Pat. Nos. 5,089,596, 5,285,887 and5,228,558, the contents of which are hereby incorporated by reference asif recited in full herein. The drive motors 20 can be in aself-contained drive assembly with a drive roller and idler rollersdriven by the driver roller and does not require external drive means.However, in other embodiments, external drive systems can be used. Thesystems 50 can include a BLDC (brushless DC) motor connector such as an8-position 2 mm-pitch header available from Amp or Tyco (179123-8 orequivalent). This type of connector provides motor winding inputs 0-2,and Hall Effect sensor inputs 0, 1, 2, and Hall Effect sensor power andground.

For the use of a multi-purpose control device (e.g., card) 10, there arethree primary differences with controlling different motors (differentmotor types/gear ratios, etc.). The first difference is the actual speedsetting for each motor (each motor rotates at the same constant speedbut this speed can be different for each motor). The second differenceis the current draw associated with each motor. The third difference isthe temperature control algorithms utilized for each motor and motorgear/box combination. Although there are many motor/gear boxcombinations, they can be reduced to three stages (stages 1, 2 and 3)for temperature control. With three motors and three stages for EC120and EC110 as well as two stages for EC100, the resulting number ofcombinations can be reduced to eight possible motor/gear box temperaturecontrol parameter settings selectable or programmable by the controldevice 10.

FIG. 1 also illustrates that the controller device 10 can include a userinterface 15 that can be accessible via an on-board HMI (Human MachineInterface) or via a connection with a remote or local computer includinga portable pervasive communications device such as a notebook, laptop,handheld or other portable computer. The controller device 10 caninclude a Jbug interface 19 which allows an operator or technician totroubleshoot or upgrade a circuit (firmware, software and the like).FIG. 6 illustrates an exemplary set of inputs and outputs.

The controller device 10 can also include an external control input 18.The external control input 18 can have various functions depending onzone type. The external control input 18 can include a 16 positionrotary switch and the motor speed can be set using a multi-positionrotary switch (replacing the potentiometer on conventional systems).There can be 16 positions: Position 1 can run the motor at ⅓ full speed,and Position 16 can run the motor at full speed. All positions between 1and 16 can control the motor at equal increments between ⅓ and fullspeed.

TABLE 2 Speed Configuration Table Rotary Switch Speed Request Percentageof Memory Selection Value Full Speed Address 0  84 33% 0327 1  95 37%0328 2 107 42% 0329 3 118 46% 032A 4 130 51% 032B 5 141 55% 032C 6 15260% 032D 7 164 64% 032E 8 175 69% 032F 9 187 73% 0330 A 198 78% 0331 B209 82% 0332 C 221 87% 0333 D 232 91% 0334 E 244 96% 0335 F 255 100% 0336

TABLE 3 Acceleration Table Rotary Switch Memory Selection Accel ValueAddress 0  10 0337 1  26 0338 2  43 0339 3  59 033A 4  75 033B 5  91033C 6 107 033D 7 123 033E 8 140 033F 9 156 0340 A 173 0341 B 189 0342 C205 0343 D 221 0344 E 238 0345 F 254 0346

TABLE 4 DECEL Table Rotary Switch Selection Decel Value Memory Address 022 0347 1 27 0348 2 33 0349 3 38 034A 4 44 034B 5 49 034C 6 55 034D 7 60034E 8 65 034F 9 71 0350 A 77 0351 B 82 0352 C 88 0353 D 96 0354 E 990355 F 104  0356

The Decel Value is the speed the motor can be slowed to before dynamicbraking is applied.

FIG. 2 illustrates an example of a conveyor system 50 with series ofconveyor zones 100-103 (shown as four but more or less can be used). Thesystem 50 include a controller device 10 (typically implemented as asingle controller card) and a peer-to-peer communication path 110 withconnections to upstream and downstream cards 110 u, 110 d (e.g.slave-type control cards), and zones 100-103 can include at least onedrive motor 20 and at least one position sensor 30, typically located ona trailing and/or leading edge portion. The controller card 10 caninclude control logic that facilitates or controls various modes ofoperation, including, for example, a Sequential Release Control and ZeroPressure Accumulation (ZPA) modes, in which serially adjacent objectsbeing transported do not touch each other.

FIG. 3 illustrates a conveyor system 50 with a target object 25 beingtransported and each zone 100-103 including a drive control 10 d for themotor 20, at least one of which is the primary logic card 10. The drivecontrols 10 d can be connected via peer-to-peer communication path 110(which can be wired or wireless) and each drive control 10 d can bepowered by a common power line (typically about +24VDC/GND). However,separate power lines and sources can be used. As shown, Zone B (101) canbe designated as reference, Zone A can be the upstream zone 102 and ZoneC can be the downstream zone 100.

FIG. 4 illustrates another embodiment of the conveyor system 50 withindividual motor drive control cards 10 d and a system card 10 thatcommunicates with a plurality of the cards 10 d. The drive motors 20 areeach in communication with at least one Hall-effect sensor 35 h.

Generally stated, embodiments of the invention use non-time basedsequential controls for zoned conveyor systems 50 (“Sequential ReleaseControl”). The control system of the conveyor system 50 can beconfigured to provide for ZPA operation. A conveyor system can include acontrol circuit 50 c that can include a controller card to drive eachzone or segment, a single controller card for all segments, severalcontroller cards to control a respective one or several segments,master-slave controller card arrangements and other logic-controlledmotor control and/or zone release systems.

The zoned conveyor systems 50 can be floor supported, wall or ceilingsuspended conveyor systems, or combinations of same. For suspendedconveyor zones, the control circuit start-up process can reduce lateralinertial forces applied to the conveyor zones upon start-up of the drivemotors of the conveyor zones which can tend to cause swaying of(suspended) conveyor zones. It is contemplated that the new controlsystems can be implemented onto existing conveyor systems of variousconfigurations without requiring costly hardware upgrades using existingelectronic and hardware components.

For singulated release, typically, a zone uses only one position sensor30, typically located proximate its downstream edge portion (FIG. 3)but, where used, the position sensor can be positioned at otherlocations as well. The system can use input from the upstream zone'ssensor 30 to monitor its upstream edge. An entry zone can have a secondsensor 30 to detect when an OBT (“Object Being Transported”) 25 entersinto its zone, since there are no zones located upstream of the entryzone. There are typically four types of zones: Entry Zone (the firstzone on a conveyor system, or if a PLC (programmable logic controller)is used, the Entry Zone controls starts at the upstream edge, thus usingsmart I/O handshaking)), Exit Zone (the last zone on a conveyor system,or if a PLC is used, this zone can control starts at the downstreamedge, using smart I/O handshaking), Transport Zone (a zone thattypically uses peer-to-peer communication to control OBT entry and exit)and a Slave Zone (a zone that simply runs when instructed to). Normalflow of the conveyor is from right to left with the drive motor 20(e.g., RollerDrive®) rotating a roller or transport surface CCW. Whengiven a signal to reverse the drive motor 20 (e.g., RollerDrive®) willrotate CW, making the direction of the conveyance travel from left toright. The reverse signal can also turn Entry Zones into Exit Zones andcan make a sensor 30 an upstream edge sensor instead of a downstreamedge sensor.

In some embodiments, the start-up of multiple conveyor segments (alsoreferred to as zones) positioned in series will occur sequentially. Thestart-up of each segment can be based on defined threshold levels forspeed and current draw of the drive motors 20 associated with arespective segment or zone. Typically, the last segment in a series (themost downstream segment in that series) will begin motion by increasingpower to the motor at a rate of change (“Ramp-Up Rate”) to bring themotor up to a desired operating speed. The Ramp-Up Rate can be aconstant rate and different Ramp-Up Rates may be used for differentzones. The control circuit 50 c can be configured to define speed andcurrent draw threshold values or ranges. Once an upstream conveyor meetsthe threshold value, a second conveyor can be directed to beginpower-up. By integrating various “Ramp-Up” rates, it is believed thatthe dynamic and power spikes can be minimized more than is possible witha timed-release system.

Typically, the controller card 10, 10 d in communication with orconnected to a last segment 100 will monitor current draw and motorspeed until threshold values for current draw and speed have been met.Once met, the first segment controller card 10 will signal the upstreamsegment 101 to activate motion. This second conveyor 101 will repeat theprocess performed by the downstream conveyor 100. The process can repeatuntil all conveyors in the series are in motion.

The controller device 10 can be configured to direct a first upstreamconveyor 101 to initiate operation based on first current draw level andspeed of the first (e.g, downstream) segment 100 and direct a secondupstream conveyor 102 to subsequently initiate operation based on adifferent second current draw level. For initial startup of zones, thedownstream zone can perform one full revolution before the upstreamstarts sending an OBT. This can help minimize power spikes from zonesstarting simultaneously.

In particular embodiments, the control device 10 can include motorcontrol sensor inputs 20 p (FIG. 1) which include Hall effect sensorinputs (FIGS. 14, 15A, 15B) and an Isense (current sense) input to acontroller (CPU or processor) to monitor current draw of the motor(FIGS. 14, 15A, 15B).

Note that the device 10 typically controls high side and low side FETS(HFETs, LFETs, respectively) (FIGS. 14, 15A, 15B) so that the LFETs areturned on during no-load stops which can speed up the stopping when notusing dynamic braking and eliminate or reduce overshoot (roller spinsforward, backward, forward, etc.).

The device 10 can include an Acceleration/Deceleration onboard rotaryswitch (which can be a 16 position on switch) that will control the rampup and ramp down rates for each motor 20. The device 10 can also includea speed rotary switch (e.g., an onboard 16 position rotary switch) thatcan control the speed of the motor (as noted above the speed can be setbetween 33%-100% of the target speed of the motor).

In other embodiments, start-up of multiple conveyor segments 100-103(FIGS. 2, 3) positioned in series can occur sequentially and thestart-up of each segment can be determined by counting the number ofmotor revolutions for a respective drive motor (usually one for eachsegment), then signaling the upstream conveyor to start after thepre-set count has been reached. The rotational count can be based on anumber of pulses detected by a sensor in communication with a rotatingmember connected to the drive motor (gear, shaft or the like) and/orconveyor support surface (e.g., rollers). This control system is alsonot time-based. One or more Hall-effect sensors 20 h (FIG. 4) in arespective drive motor 20 can be used to provide the revolution countsignal (e.g., Hall-effect signal pulses). However, alternative sensorscan be used as well for this input. Counting revolutions (typicallypulses associated with the revolutions), then staggering the start-up isalso believed to be an effective way of implementing a staggered releasethat can reduce and/or minimize start-up current draw and dynamicloading of the system. The process can repeat until all conveyors in theseries are in motion. For suspended conveyor zones, this process canreduce lateral inertial forces applied to the conveyor zones uponstart-up of the drive motors of the conveyor zones which can tend tocause swinging of the conveyor zones.

The control circuit 50 c (or card 10) can be configured to operate withconveyor zones having different gear box ratios. For example, variousconveyor zones 100, 101, 102, 103 may include one or more of each of alow ratio (typically 4:1), a standard ratio (above 4:1, typically about16:1), or high ratio (above 16:1, typically up to about 96:1). Each gearbox ratio is associated with a different number of rotations used to getthe drive motor 20 and associated zone up to a desired speed at aparticular defined ramp up rate. The control circuit 50 c (e.g, card 10)can be configured to define the number of counts associated withinitiation of the next zone based on what type of gear box ratio is inthe current zone undergoing initiation (e.g., whether it is a is astandard, high or low ratio gear box). The controller card 10 and/orcontrol circuit 50 c can be configured to electronically determine thegear box ratio associated with each zone based on the type of drivemotor, serial number, part number, test signal sent to the drive motoror zone or other interrogation means or the control circuit may acceptuser input to identify the gear ratio for each zone during anon-boarding installation.

In some embodiments, the controller card 10 may also include singulatedrelease control logic. The singulated release control logic can define atravel distance associated with belt displacement by counting the numberof Hall effect pulses associated with drive motor revolutions (usingHall-effect sensors and a motor revolution counter associated with beltdisplacement), rather than using a predetermined position and downstreamposition sensor, to control start and stop of adjacent conveyor zones.The control logic can allow for different distance settings that can beused depending on a customer's spacing needs without requiring anyphysical movement of sensors. For example, a defined number of motorrevolutions can be associated with a defined length and this count canbe electronically incremented or decremented to adjust load spacingwithout requiring physical movement of the sensor(s).

The controller card 10 can include a Displacement Learning Module whichmay use two position sensors to establish actual distance associatedwith revolutions and/or belt displacement for a particular zone, butthis part of the operation is not used for singulated release; it isused for calibration or parameter setting of the distance used for themotor revolution/belt displacement counter for subsequent singulatedrelease mode.

In use, singulated package release can be performed by monitoring aposition sensor at the end of an upstream conveyor in combination withcontrol of conveyor belt displacement of an immediate downstreamneighboring conveyor segment/zone. The upstream conveyor sensor cansense the leading edge of a package. Once the leading edge is sensed,this conveyor will stop. The downstream conveyor can continue movinguntil the previous package has moved a defined distance along thedownstream conveyor. The distance is determined by a controller (e.g.,the downstream controller) counting motor revolutions, e.g., Hall-effectpulses associated with the motor revolutions, to advance the belt, andhence the package, a defined distance associated with a defined numberof pulses. This distance may vary slightly. Once the defined distance isobtained by the downstream conveyor, the control circuit, e.g.,downstream controller, can reset its motor revolution/belt displacementcounter and signal the upstream conveyor to activate to move the nextpackage onto the downstream conveyor. Stated differently, once theprescribed distance has been obtained by the downstream conveyor, thedownstream controller can reset its motor revolution counter, signalrelease of the package on the downstream conveyor and signal theupstream conveyor to activate, thus moving the first package off thedownstream zone and the next package onto the downstream conveyor zonefrom the upstream conveyor zone. To restart the zones, a “SequentialRelease Control” mode can be used as described above to reduce currentdraw spikes and/or dynamic sway issues associated with two conveyorsstarting up simultaneously. Thus, in some embodiments, the upstream anddown stream conveyors do not start-up simultaneously.

The belt displacement and/or number of motor revolutions can bevariables that are set using a Hyper-terminal or other interface atinstallation or set-up. The values for the variables can be derived froma look-up table (electronic library or user reference manual) thatincludes displacement variables for combinations of motors and gearboxes. The singulated release logic can be implemented using a singlecontroller card for conveyors associated with the singulated release ormay be distributed over several controller cards. Conveyors upstreamand/or downstream of the two conveyors can be controlled via the samecontroller card for the singulated mode and may also use existingcontroller cards.

In some embodiments, the controller device 10 and/or control circuit 50c can include a “Displacement Learn Mode” for use at installation orset-up that associates a defined travel distance with a particular zonebased on motor type, gear ratio, belt displacement, zone length and thelike. For example, an installer can set the defined distance associatedwith belt displacement, revolutions or motor type during installation byputting the controller card in a singulated release mode using theon-card electronics 10 e, such as dip switches, and then providing aninput signal to the second conveyor's position (typically optical)sensor input port when the package 25 on the conveyor reaches apreferred position on the belt. This input can be supplied to one ormore of the controller cards' 10, 10 d (optical) sensor input port usingan actual position (e.g., optical) sensor or a simulated electricalinput. The controller 10 can capture the belt's displacement when itreceives the signal. Once the count has been captured, the sensor port22 (FIG. 1) can be disabled for use with singulated release positionsensing for singulated release run modes.

Note that this approach creates a scenario where the (optical) sensor 30is not needed on the downstream conveyor for singulated release and mayprovide cost savings over conventional systems. If the installer or userneeds to reset the displacement (load travel distance or load spacing)setting, this can be performed in a number of ways. For example, thedisplacement setting can be reset using the electronics on thecontroller card, e.g., dip-switches on the card, by switching singulatedrelease mode off/on. The card 10 would then be ready to accept a newdisplacement value.

It may also be possible to reset the displacement setting by providingmultiple input signals to the card's sensor port in rapid succession,for example 10 pulses in less than 5 seconds. This relearn or reset modecan eliminate the need for the user to touch the controller card 10 toreset the displacement setting. Also, the displacement setting can beelectronically reset by providing a coded pulsed signal to the card'soptical sensor port. For example, the system can be configured totransmit series of pulses in a defined format and time constraintperiod. For example, the system can transmit 3 short pulses, followed by3 long pulses, followed by 3 short pulses; all occurring within a timeconstraint. The use of a “Learning Displacement Mode” can be used in thealternative to manually setting the displacement variable at set-up orinstallation by a user (e.g., via the Jbug interface or a Hyper-terminalinterface).

The controller device 10 can operate with the “Learn Mode” using two ormore variables. In some embodiments, the variables are identified assiHES_Counter, siHesChangeCount. In this embodiment, the siHES_Counterstores how many HES changes occurred from the time an OBT 25 startedinto the zone until the leading edge of the OBT 25 reaches that zone'ssensor. This number is used to determine zone length. siHesChangeCountincrements by one every time there is a HES change. This variable isreset to zero every time an OBT 25 starts to enter into a zone, and iscompared against siHES_Counter to determine when the OBT 25 should be atthe end of the zone. This is also used to check for Jam1 errors, if theOBT 25 does not get to the zone's sensor by the end of the count, thenthe motor turns off.

Initially siHES_Counter is 0xFF(−1), which means that the zone has notlearned it zone length. Therefore, when an OBT's leading edge firstenters the zone, the siHesChangeCount is set to zero then beginscounting HES changes until the leading edge of the OBT gets to thezone's sensor. The firmware then sees that siHES_Counter is 0xFF so ittakes the final value of siHesChangeCount and stores it to siHES_Counterand saves the value into EEPROM, so that the length can be rememberedafter being powered down. Once siHES_Counter is set, every time an OBTenters the zone it is compared with siHesChangeCount to determine whenthe OBT should be at the end of the zone.

This value may be reset at anytime by jumping the Learn mode jumper forapproximately 2 sec. When this occurs, siHES_Counter is set back to0xFF(−1), Therefore, when a new OBT's leading edge enters the zone, thezone begins learning the zone length again.

-   -   A) OBT's leading edge is at the upstream sensor. Zone 2 begins        counting everytime the HES changes while the motors run.    -   B) OBT's leading edge is at the zone's end sensor. Final count        of siHesChangeCount is stored to siHES_Counter    -   C) Zone length is now learned and ready for new OBTs        Jam1/OBT Removed from Zone Detection    -   A) OBT's leading edge is at the upstream sensor. Zone 2 begins        counting everytime the HES changes while the motors run.    -   B) As the OBT travels through the zone, siHesChangeCount is        compared against siHES_Counter. If the OBT has not reached the        zone's sensor (as shown in section B above) by the time        siHesChangeCount is >=siHES_Counter, then there must be a jam or        the OBT has been removed. Turn off zone's motor and set zone        state to empty.    -   C) Zone is now ready to accept new OBT.

It may be preferable that the (optical) position or proximity sensor 30remains in use for control uses other than package displacement when insingulated release mode. For example, as a safety precaution, theposition or proximity sensor 30 may be used to sense accidental “beltrun-off” where a package continues to advance past its prescribeddisplacement. This might occur during package jams or controllermalfunction. In such a scenario, the controller card 10 could controldisplacement to a distance just short of the captured displacementvalues (Displacement Count−X Counts) so that the installer could keep aposition/proximity (e.g., optical) sensor in location and active forpurposes other than singulated release displacement control as asafety/malfunction sensing input.

Embodiments of the present invention may take the form of an entirelysoftware embodiment or an embodiment combining software and hardwareaspects, all generally referred to herein as a “circuit” or “module.”

Furthermore, embodiments of the present invention may take the form of acomputer program product on a computer-usable storage medium havingcomputer-usable program code embodied in the medium. Any suitablecomputer readable medium may be utilized including hard disks, CD-ROMs,optical storage devices, a transmission media such as those supportingthe Internet or an intranet, or magnetic storage devices. Some circuits,modules or routines may be written in assembly language or evenmicro-code to enhance performance and/or memory usage. It will befurther appreciated that the functionality of any or all of the programmodules may also be implemented using discrete hardware components, oneor more application specific integrated circuits (ASICs), or aprogrammed digital signal processor or microcontroller. Embodiments ofthe present invention are not limited to a particular programminglanguage.

Computer program code for carrying out operations of data processingsystems, method steps or actions, modules or circuits (or portionsthereof) discussed herein may be written in a high-level programminglanguage, such as Python, Java, AJAX (Asynchronous JavaScript), C,and/or C++, for development convenience. In addition, computer programcode for carrying out operations of exemplary embodiments may also bewritten in other programming languages, such as, but not limited to,interpreted languages. Some modules or routines may be written inassembly language or even micro-code to enhance performance and/ormemory usage. However, embodiments are not limited to a particularprogramming language. It will be further appreciated that thefunctionality of any or all of the program modules may also beimplemented using discrete hardware components, one or more applicationspecific integrated circuits (ASICs), or a programmed digital signalprocessor or microcontroller.

The present invention is described in part with reference to flowchartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products according to embodiments of the invention. Itwill be understood that each block of the flowchart illustrations and/orblock diagrams, and combinations of blocks in the flowchartillustrations and/or block diagrams, can be implemented by computerprogram instructions. These computer program instructions may beprovided to a processor of a general purpose computer, special purposecomputer, or other programmable data processing apparatus to produce amachine, such that the instructions, which execute via the processor ofthe computer or other programmable data processing apparatus, createmeans for implementing the functions/acts specified in the flowchartand/or block diagram block or blocks.

These computer program instructions may also be stored in acomputer-readable memory that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperational steps to be performed on the computer or other programmableapparatus to produce a computer implemented process such that theinstructions which execute on the computer or other programmableapparatus provide steps for implementing some or all of thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowcharts and block diagrams of certain of the figures hereinillustrate exemplary architecture, functionality, and operation ofpossible implementations of embodiments of the present invention. Inthis regard, each block in the flow charts or block diagrams representsa module, segment, or portion of code, which comprises one or moreexecutable instructions for implementing the specified logicalfunction(s). It should also be noted that in some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the figures. For example, two blocks shown in successionmay in fact be executed substantially concurrently or the blocks maysometimes be executed in the reverse order or two or more blocks may becombined, depending upon the functionality involved.

FIG. 5 is a schematic illustration of a control circuit or dataprocessing system that can be used to control sequential start up ofzoned conveyor segments. The circuit and/or data processing system maybe incorporated in a digital signal processor in any suitable device ordevices. As shown in FIG. 5, the system includes at least one processor410 and memory 414 that communicates with the processor via anaddress/data bus 448. The processor 410 can be any commerciallyavailable or custom microprocessor. The memory 414 is representative ofthe overall hierarchy of memory devices containing the software and dataused to implement the functionality of the data processing system. Thememory 414 can include, but is not limited to, the following types ofdevices: cache, ROM, PROM, EPROM, EEPROM, flash memory, SRAM, and DRAM.

FIG. 5 illustrates that the memory 414 may include several categories ofsoftware and data used in the data processing system: the operatingsystem 452; the application programs 454; the input/output (I/O) devicedrivers 458; and data 455. The data 455 can include defined ramp-uprates, defined current draw threshold values of drive motors, speedthreshold values of drive motors, rotation count levels (hall effect)and the like. FIG. 5 also illustrates the application programs 454 caninclude a Drive Motor Monitoring Module 450 and a Staggered SequentialControl Module 451 for the different conveyor segments.

As will be appreciated by those of skill in the art, the operatingsystems 452 may be any operating system suitable for use with a dataprocessing system, such as OS/2, AIX, or zOS from International BusinessMachines Corporation, Armonk, N.Y., Windows CE, Windows NT, Windows95,Windows98, Windows2000, WindowsXP, Windows Visa, Windows7, Windows CE orother Windows versions from Microsoft Corporation, Redmond, Wash., PalmOS, Symbian OS, Cisco IOS, VxWorks, Unix or Linux, Mac OS from AppleComputer, LabView, or proprietary operating systems.

The I/O device drivers 458 typically include software routines accessedthrough the operating system 452 by the application programs 454 tocommunicate with devices such as I/O data port(s), data storage 455 andcertain memory 414 components. The application programs 454 areillustrative of the programs that implement the various features of thedata processing system and can include at least one application, whichsupports operations according to embodiments of the present invention.Finally, the data 455 represents the static and dynamic data used by theapplication programs 454, the operating system 452, the I/O devicedrivers 458, and other software programs that may reside in the memory414.

While the present invention is illustrated, for example, with referenceto the Modules 450, 451 being application programs in FIG. 5, as will beappreciated by those of skill in the art, other configurations may alsobe utilized while still benefiting from the teachings of the presentinvention. For example, the Modules and/or may also be incorporated intothe operating system 452, the I/O device drivers 458 or other suchlogical division of the data processing system. Thus, the presentinvention should not be construed as limited to the configuration ofFIG. 5 which is intended to encompass any configuration capable ofcarrying out the operations described herein. Further, one or more ofmodules, i.e., Modules 450, 451 can communicate with or be incorporatedtotally or partially in other components, such as separate or a singleprocessor or different circuits in the control system of the zonedconveyor system.

The I/O device drivers typically include software routines accessedthrough the operating system by the application programs to communicatewith devices such as I/O data port(s), data storage and certain memorycomponents. The application programs are illustrative of the programsthat implement the various features of the data processing system andcan include at least one application, which supports operationsaccording to embodiments of the present invention. The data representsthe static and dynamic data used by the application programs, theoperating system, the I/O device driver and the like.

The control device 10 and/or system control circuit 50 c can include thefollowing primary logic, monitoring and control functions.

Initialization

Initialize all the I/O ports, defining whether they are inputs, outputs.

Clear all Registers Clear SRAM Initialize EEPROM

Initialize the Jbug parameter tableSet NPN/PNP inputs at midpoint so they have to ramp up or downInitialize analog bus voltage at minimumDo an initial read of the Hall Effect Sensors

Initialize the UART Initialize the RTI Initialize the Timer

Initialize the AD converterInitialize the watchdog timerRead setup switchesDetermine motor type from setup switches and set proper parametersvalues for that motor

Motor Control

Decay Velocity routine removes 1/128 of value of 16 bit Velcocity calledevery 300 uS for EC100 and 600 uS for the EC110 and EC120Monitor HES changes—update velocity and position when change occursVelocity controlPosition control

Drivemode Drive the FETS

Translate Analog Speed to Relative speed request

ADC

Creates ADC lookup tableInitialize ADC function to be called by InitializationFunction to do conversionFunction to start conversionFunction to average the conversion result

Timers

50 uS timer1 mS timer1 Second timer

Fail Actions

Handle warning actionsHandle fault actionsControl LEDs depending on the situation

System Control

Reads analog inputs from external controlReads digital inputs from Peer-to-PeerDetermines system reversal

ZPA

Determines zone typeTranslates the various analog and digital inputs to be used by the ZPAcontrol algorithmHandles control of zoneHandle ZPA timers

Singulation

Handles standard singulation and enhanced singulation

Thermal Model Monitor Current

Calculate expected motor temperature

Jbug

Handles access to parameter table through UART

Learn Routine

Measure distance between upstream sensor and downstream sensor of a zoneby counting hall effect pulses/changes. As discussed above, the pulsecount can be associated with a desired distance/length of a zone andthis result can be electronically saved in memory such as in a look-upchart or parameter table. The system can use this value this todetermine if an OBT has reached an end of the zone.

FIG. 7 is a flow chart of primary monitoring steps (blocks 100-144) thatcan be used to carry out embodiments of the present invention.

FIGS. 8A and 8B are flow charts of operations that can be used for realtime interrupt (RTI) for different motor types. FIG. 8A shows a seriesof decisions and steps (blocks 150-176). FIG. 8B shows a similar seriesof decisions and steps (blocks 180-199).

FIGS. 9-15A are examples of components or sub-circuits of the device 10according to embodiments of the present invention. FIG. 9 illustrates anexample of a sensor interface circuit 200 for sensor paths 30 p (FIG.1). FIG. 10 illustrates an exemplary 5V power supply circuit 205 for thedevice 10. FIG. 11 illustrates an exemplary upstream peer-to-peerinterface circuit 210 for the device 10 while FIG. 12 illustrates anexample of a for a downstream peer-to-peer interface circuit 215 110 d(FIG. 1). FIG. 13 is an example of a circuit diagram of a system controlcircuit 220 for the device 10. FIG. 14 is an example of a motor controlcircuit 225 for the controller device 10. FIG. 15A is an example of amain processor unit circuit 240 for the device 10 (FIG. 1).

The control device 10 can include the following product functions.

Motor Control

-   -   1) When an OBT begins to enter into a zone, the software will        turn on that zones motor.    -   2) Runs motor in forward or reverse direction depending on        direction input    -   3) Software will also monitor current draw of motor over time,        and use Temperature Model algorithm to determine temperature of        the motor    -   4) Board temp is also monitored, will alter current to motor        based on certain criteria    -   5) The onboard rotary switch and Speed In input will be        monitored to know when and how much to adjust the speed of the        motor    -   6) Monitor Hall Effect Sensors to monitor current speed and        direction against expected speed and direction and dynamically        adjusts accordingly.

ZPA Functionality

Standard Singulation

-   -   1) handles the control of zones to keep OBTs a certain distance        apart, thus distributing a more uniform load across the motors.        Also decreases the chance of OBT jams.    -   2) Software uses the Peer-to-Peer ports to communicate with        adjacent zones upstream and downstream. This allows the software        to make decisions based on inputs of the adjacent zones.    -   3) Monitors L-stop input to detect when a user is manually        stopping a zone so that it can alert other zones to this event,        so they may respond to this action accordingly.    -   4) Monitors Sensor 1 to detect the presence an OBT on the        downstream edge of a zone. Then the software will check to see        if it is ok for the OBT to enter the next zone through the        Peer-to-Peer. It will also check to see if the upstream is        active. If it is active the same time as the zone's sensor then        it must handle the oversized OBT.    -   5) Monitors Sensor 1 of the upstream zone, to know when a new        OBT is ready to enter into its zone. Will check to see if an OBT        has currently entered the zone. If it has then it will tell the        upstream to accumulate the package till the previous OBT has        completely left its zone.    -   6) Monitors for Jog command, if the jog command is received        anytime during singulation, then all sensor inputs are ignored,        and the motors are blindly ran.    -   7) If the zones are ran in reverse, then current zone's sensor        becomes the upstream zone, and the previous upstream sensor will        then become the downstream sensor.    -   8) Check and monitor for Jams. If an OBT does not reach the        sensor after a predetermined distance count, then a Jam Type 1        has occurred. If a Jam occurs at the sensor then a Jam Type 2        occurs. Jam Type 2 is time based, a package should clear the        downstream sensor after a preset time. If it does not then a Jam        is detected and the Fault LED is lit steady until the Jam is        clear.

Enhanced Singulation

-   -   1) Instead of waiting for an OBT to completely clear out of a        zone before allowing the next one in, Enhanced Singulation        allows the next OBT to enter once the previous OBT starts        exiting the zone. This allows a greater throughput but also        increases the chance of a Jam occurring.

Jbug

-   -   1) Allows a user to read/write to SRAM and EEPROM for debugging        or changing parameters.

Warning/Fault outputs

-   -   1) Handles the LED output for specific warning or fault        conditions, so a user may quickly be able to diagnose an issue.

Thermal Model

-   -   1) The thermal model can run in defined cycles, such as once per        second, and calculates the expected temperature (rise) of the        motor.    -   2) uses model coef 1-6 and measured current over time to        determine the motor temperature.    -   3) model coef5 is the decay timer in seconds for the case        temperature, it divides the case temp by 256 each time the        tinier elapses.    -   4) model coef6 is used to scale the current measurement into        0.1A units    -   5) model coef1 is used to scale current to take into account for        winding resistance    -   6) if the motor is below 70% of target speed then it is deemed        slow. A flag is raised to let the model know to use model coef2        to scale the current further to take into account the increased        heat generated due to the slow condition.    -   7) if the motor is stalled then the current is scaled further        with model coef3    -   8) the current is then squared and then sum in result with the        case temp.    -   9) then sum in ((Vmon*I)/64*model coef4)/256

The controller device 10 can work independent of user interaction fornormal operation. Typically, the only user interaction occurs duringinstallation of the conveyor system and maintenance. The controllerdevice 10 can include one or more of the below defined parameterassumptions and functions.

-   -   A motor can be considered stalled when under a selectable        parameter for ˜125 mS    -   A motor can be considered slowed when under a selectable        parameter for ˜125 mS    -   The thermal model can update the expected case temperature about        every one (1) second.    -   Decelerating OBT before braking when the accumulate signal is        received to take at most about 1 second.    -   For initial startup of zones, the downstream zone can perform        one full revolution before the upstream starts sending an OBT.        This will help minimize power spikes from zones starting        simultaneously.

An example of a thermal model is provided below.

Model Coefficients E/G Coef1—phase resistance 153/142 Coef2—currentscaler for motor in slow state 222/234 Coef3—current scaler for motor installed state 234/245 Coef4—gearbox losses and thermal cap 18/16Coef5—Time period in seconds to decay temp 8 Coef6—scales current into.1A units 159

Temperature Model Algorithm

CaseTemp=CaseTemp+(Î2/256)+(V*I/64)*(model_coef4/256)

Decay Case Temp

caseTemp=caseTemp−(caseTemp/256)//when timer set by model_coef5=0

The current can be scaled depending on certain conditions and used inthe algorithm above.

Scale Current to 0.1A Units

Read Current value(I*model_coef6)/128//scales current to 0.1A unitsStore the result into R16

Scale Factor for Winding Resistance (I*model_coef1)/128 Current Due toNegative Current

Check result to see if current is negative

-   -   If it is then I=0

Current Due to Dynamic Braking

Check to see if motor is dynamic braking

-   -   if it is then I=0        save a copy of R16 (the current scaled to 0.1A units)

Calculate and Sum in Thermal Rise

(I*model_coef1)/128//scale factor for winding resistance

-   -   If motor in slow state        -   Scale the current//(I*model_coef2)/128    -   if motor in a stalled state        -   Scale the current//(I*model_coef3)/128            caseTemp+=Îb 2/256

Completes Case Temperature Calculation

caseTemp+=(V*I/64)*(model_coef4/256)//I above is current scaled by model_coef6

It is contemplated that a Case Temperature Thermistor may be added inthe future to more precisely and/or accurately determine the actualtemperature of the motor. The firmware can be modified to handle the newinput and change how the thermal model is used.

In some embodiments, the zoned control system 50 allows for five statesfor a respective zone in standard singulation and nine states inenhanced singulation. These states are summarized below and the citedfigures show exemplary operations that may be used during these states.However, it is noted that other steps can be used to carry out thefunctionality of the states.

Transport Zone with Standard Singulation

-   -   5 States    -   0. Zone empty (see FIG. 16 for exemplary operations)    -   1. Object entering zone (see FIG. 17 for exemplary operations)    -   2. Object in zone heading toward sensor (see FIG. 18 for        exemplary operations)    -   3. Holding object at sensor (see FIG. 19 for exemplary        operations)    -   4. Object exiting Zone (see FIG. 20 for exemplary operations)

Transport Zone with Enhanced Singulation

-   -   9 States    -   0. Zone empty (see FIG. 21 for exemplary operations)    -   1. Object entering zone (see FIG. 22 for exemplary operations)    -   2. Object in zone heading toward sensor (see FIG. 23 for        exemplary operations)    -   3. Holding object at sensor (see FIG. 24 for exemplary        operations)    -   4. Object exiting Zone (see FIG. 25 for exemplary operations)    -   5. Object exiting while another enters (see FIG. 26 for        exemplary operations)    -   6. Exiting object held, another was entering (see FIG. 27 for        exemplary operations)    -   7. Object still exiting, 2^(nd) object already entered (see FIG.        28 for exemplary operations)    -   8. Exiting object held, 2^(nd) object already entered (see FIG.        29 for exemplary operations)        The device 10 (e.g., controller card) can be configured so that        singulation mode is selected by sw3 on the dip switch (0 for        enhanced, 1 for standard)

FIG. 30 illustrates a circuit similar to that discussed above withrespect to FIG. 5. However, this circuit includes a Singulated TransportModule 1451 and a Learn Displacement Module 1450 for a conveyor zone(100-103, FIGS. 2-4) to electronically learn a distance associated witha number of revolutions as discussed above.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although a few exemplary embodiments ofthis invention have been described, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe claims. In the claims, means-plus-function clauses, if used, areintended to cover the structures described herein as performing therecited function and not only structural equivalents but also equivalentstructures. Therefore, it is to be understood that the foregoing isillustrative of the present invention and is not to be construed aslimited to the specific embodiments disclosed, and that modifications tothe disclosed embodiments, as well as other embodiments, are intended tobe included within the scope of the appended claims. The invention isdefined by the following claims, with equivalents of the claims to beincluded therein.

1. A zoned conveyor system for transporting a series of loads, comprising: a series of conveyor zones including a downstream conveyor zone and a plurality of upstream conveyor zones, each conveyor zone including at least one drive motor for operating each respective conveyor zone to advance the loads along the conveyor system; and a control circuit in communication with each conveyor zone at least one drive motor, wherein the control circuit is configured to monitor during start-up for a respective conveyor zone at least one of: (i) current draw and speed of a respective drive motor as the motor goes from an unpowered state to an operational state; or (ii) a number of revolutions of a respective drive motor as the motor goes from an unpowered state to an operational state, and wherein the control circuit is configured, after operation of the upstream and the downstream conveyor zones are stopped to maintain stationary any loads carried by the upstream and downstream conveyor zones, to resume operation of the upstream and downstream conveyor zones by first initiating operation of the downstream conveyor zone, and subsequently sequentially controlling initiation of operation of each upstream conveyor zone, wherein the control circuit is configured to initiate operation of one of the upstream conveyor zones based on one of the following: (i) when the drive motor of the conveyor zone downstream therefrom reaches a defined current draw and speed; or (ii) when the drive motor of the conveyor zone downstream therefrom has reached a defined number of rotations, so that operation of each conveyor zone is initiated in a controlled sequential manner in response to when the drive motor of the conveyor zone downstream therefrom reaches the defined current draw and speed or the motor has turned the defined number of revolutions.
 2. The system of claim 1, wherein the control circuit is configured to increase power to a respective drive motor at a constant rate of change from the unpowered state to the operational state, and wherein the control circuit is configured to direct the sequential operation using the monitored current draw and speed of a respective drive motor.
 3. The system of claim 1, wherein the drive motors each include at least one integral Hall-effect sensor, and wherein the control circuit is configured to direct the sequential operation based on motor revolution count using a pulse count detected by the respective Hall-effect sensors.
 4. The system of claim 1, wherein the control circuit is configured to ramp up at least one of the zones at a different speed from other zones to thereby operate with improved power management and a smooth system ramp-up.
 5. The system of claim 1, wherein the control circuit comprises a primary controller card that communicates with drive motor controller cards at upstream and downstream conveyor zones, wherein the primary controller card includes an onboard processor that includes the sequential start-up logic and current draw and speed threshold values used to determine when to initiate start-up to the different zones.
 6. The system of claim 1, wherein the control circuit is configured to operate with conveyor zones having different ratio gear boxes with each respective gear box ratio associated with a different number of rotations or current draw to raise the drive motor and associated zone up to a desired speed.
 7. A controller circuit device for a zoned conveyor system, comprising: a control circuit comprising a sequential release operational mode for a zoned conveyor system having a downstream zone and a plurality of upstream conveyor zones in communication with a drive motor for each conveyor zone, wherein the control circuit is configured to monitor current draw and speed of the respective drive motors during start-up, and wherein, in the sequential release operational mode, the control circuit is configured to initiate operation of the upstream conveyor zones based on when a drive motor of the conveyor zone downstream therefrom reaches a defined current draw and speed so that operation of each conveyor zone is initiated in a controlled sequential manner in response to when the drive motor of the conveyor zone downstream thereof reaches a defined current draw and speed.
 8. The device of claim 7, wherein the device is a single controller card that is configured to control start-up of different conveyor zones using different defined current draw thresholds and speeds.
 9. The device of claim 7, wherein the device is configured to cooperate with conveyor zones that have different drive motors.
 10. The device of claim 7, wherein the device comprises a motor temperature monitoring circuit that uses a predictive thermal model that considers whether a motor is associated with a zone using dynamic braking.
 11. The device of claim 7, wherein the device has a motor control circuit with a plurality of low side and high side FETs in communication with at least one drive motor of at least one conveyor zone, and wherein during no-load stops the low side FETs are turned on to reduce overshoot during the no-load stops.
 12. The device of claim 7, further comprising a look-up table of drive motors, gear ratios and associated threshold values for speed and current draw used for the sequential release mode.
 13. The device of claim 7, wherein the control circuit is configured to direct a respective drive motor to ramp up to speed at a constant ramp up rate.
 14. The device of claim 7, wherein the control circuit is configured to direct different conveyor zones to ramp up at different speeds while monitoring current draw.
 15. The device of claim 7, wherein the control circuit is configured to direct a first upstream conveyor to initiate operation based on first current draw level, and direct a second upstream conveyor to initiate operation based on a different second current draw level.
 16. A method of operating a zoned conveyor system, comprising: stopping operation of a downstream and a plurality of upstream conveyor zones to maintain stationary any loads supported by the conveyor zones; and automatically re-starting the conveyor zones by sequentially initiating operation of the downstream conveyor zone and the upstream conveyor zones by first initiating operation of the downstream conveyor zone, and subsequently sequentially controlling initiation of operation of each upstream conveyor zone, wherein the re-starting step is carried out by: monitoring current draw and speed of a drive motor associated with the downstream conveyor zone; then automatically initiating operation of an adjacent first upstream conveyor zone when the downstream drive motor reaches a predefined current level and speed; monitoring current draw and speed of a drive motor associated with the first upstream conveyor zone; then automatically initiating operation of a second upstream conveyor zone adjacent to the first upstream conveyor zone when the drive motor of the first conveyor zone reaches a predefined current draw and speed, wherein operation of each conveyor zone is initiated in a controlled sequential manner in response to when the drive motor of a conveyor zone downstream thereof reaches a predefined current draw and speed during start-up.
 17. The method of claim 16, wherein the predefined current draw and speed for at least one conveyor zone is different from the others.
 18. A method of operating a zoned conveyor system, comprising: stopping operation of a downstream and a plurality of upstream conveyor zones to maintain stationary any loads supported by the conveyor zones; and automatically re-starting the conveyor zones by sequentially initiating operation of the downstream conveyor zone and the upstream conveyor zones by first initiating operation of the downstream conveyor zone, and subsequently sequentially controlling initiation of operation of each upstream conveyor zone, wherein the re-starting step is carried out by: counting a number of motor revolutions of a drive motor associated with the downstream conveyor zone; then automatically initiating operation of an adjacent first upstream conveyor zone when the downstream drive motor revolution count reaches a predefined level; counting a number of motor revolutions of a drive motor associated with the first upstream conveyor zone; then automatically initiating operation of a second upstream conveyor zone adjacent to the first upstream conveyor zone when the drive motor revolution count of the first conveyor zone reaches a predefined level, wherein operation of each conveyor zone is initiated in a controlled sequential manner in response to when the drive motor of a conveyor zone downstream thereof reaches a predefined revolution count during start-up. 